ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 547 



B. INVERTEBRATA. 



Effect of High Pressure on the Vitality of Micro-organisms.* 

 — A. Certes describes some experiments which he has made on fresh- 

 water and marine micro-organisms. 



At a pressure of 100 to 300 atmospheres, maintained for 7, 24, 

 48, and 72 hours, some were killed; Chlamydococcihs pliimalis were 

 as lively as when they were put in the apparatus 7 hours previously ; 

 Paramecium colpoda and Vorficellce (300 atmospheres for 48 hours) 

 showed the " latent life " of Dr. Regnard.f The marine infusoria 

 Euplotes charon, E. patella, and Pleuronema marina retained the 

 power of motion, while Holosticha fiava and Actinophrys were 

 dead. 



After 36 hours at a pressure of 520 atmospheres, the Chlamydo- 

 cocci were mostly in the latent state, the completely green individuals 

 having resisted the pressure better than those which were turning 

 red. Eotifers were taken out in full activity, while Tardigrades 

 revived after a time. 



In a case of bacteridian anthrax, blood submitted to a pressure 

 of 600 for 24 hours maintained its full virulence. 



Micro-organisms of the Deep Sea.| — The researches of A. 

 Cortes on water and ooze from great depths tend to show that microbes 

 that can live without air are absent from the bottom, while air- 

 breathing forms are there present. The series of cultivation experi- 

 ments which he carried on showed that the micro-organisms of deep- 

 eea water were always much smaller and more active than those of 

 the ooze. Ciliated or flagellate infusoria were absent. Successive 

 cultivations resulted in the appearance of a number of large bacilli 

 in active spore-formation. It has not yet been possible to decide 

 whether the organisms found at great depths are identical with those 

 already known. 



The researches of Kegnard have shown that soluble ferments are 

 not aflfected by pressure ; under the influence of 1000 atmospheres 

 starch was converted into sugar under the action of saliva. The 

 other results obtained have been already noted.§ 



Origin and Formation of Glairine or Baregine.|| — Supplement- 

 ing a former paper on this subject, N. Joly describes the result of his 

 observations on the origin and mode of formation of glairine or 

 bar^gine in the sulphurous thermal waters of the Pyrenees. Micro- 

 scopical examination, with a low power, of glairine and "sulfurairo " 

 in the course of formation revealed the presence of a very consider- 

 able number of animalcules, Nats, Cyclops, &c., in the full vigour of 



* Journ. fie Micro;<r., viii. (ISS-l) pp. 291-3. 



+ Sec this .Journal, <intf:, p. J}ti2. 



: Nftturforafhcr, xvii. (1884) pp. 11)3-1. 



§ fv'o thJH Journal, "ulc, p. HHi. 



il Mem. Acad. Sci. Toulouse, v. (1883) pp. 118-2.> (1 pi.). 



